Spark-plug.



W. H. MGNUTT.

SPARK PLUG.

APPLIOATIONHLBD AUGA, 1910.

Patented Nov. 8, 1910.

.M M. w.

wh/casco n /ff l 6 0 'raison is distributed UNITED- sTATEs PATENT oinrIfCE-` I Application led August 4, 1910. Serial No. 575,508; I

v Be it known that I, WIILIAM H. MoNU'rr,- direct contact with' the explsiol ame tends a citiaen o f the United States, residing ,at tobecome coated with -id with the New York inthe county ofNew- York and usual structures in spark e iiis'ii'la# 60 6 State of ew York, have invented certain tion is exposed more or legs.' lic i l the new and useful Im rovements in Spark- Haine. Sometimes the 'lati placed Plugs, of which the ollowing is a speciicfaat lthe base of 'a restricted tion.

mun'icating with the This invention relates to s ark plugs; and through a more or less 'circhi t'ou 4 10 comprises a spark plug or an explosion but this merely-delays tlife" sootin .motor provided with an .electrode or pole lchamber iS', relatively. S piece in coperative relationship to an inend for gases and tends j closing foramnous member, saidoramiwith soot, thisl tendency being the"'grater nous member constitutinga second pole piece the more circuitus the-' communication. 70

15 and-having a sparking orifice in. coperat-iye And in the alternate orn ress'ionggand ex- Vrelationshlp to the first pole piece, and hav .pension Of Vthe g'SeS i "'I "i i i ing a plurality of smaller distributed ila-me or lessofr` the soot ges x extinguishing jorices; all as more fully 'Small Chamber an leeVeQ-tli hereinafter set forth and as claimed. Occasionally @the insulin-tifo '20 In the operation ofinternal' combustion, a metal cap havin a per-f motors, considerable diiculty is'always-'exl with .the end of l1 4e 'spar-l -perienced with the spark forming devices being produced between" employed for ignitiii theexplosive mixture Walls. Of thePelfOItiOl b in the 'engine cylin er, for the reason .that Smilar'reaSIlSyhaS b@ i 25 the insulating surfaoesjhetween the pole lexcellent soot-accumulati piecesV tend to' become' covered with an adee t Where vtheSOO 00Min j erent. coating of carbon or soot which, inl fsu ation between the eleetr Atime, short circuits thecurren't around thev r-Spal'kl terminals it -d'oes pole gap.- In -a spark plug, there must "of :Where Aormed on the ins '30 necesy be a layer of'insulation, which is Circuit resulting in' ti gene y- 'of porcelain, between the pole. use of an engine untilftj pieces and there ismuch diiiiculty in keepbeen 4takenoutand illes-rin ing the surface of this insulating layer free :freed .fIOlIill adhering S 1 from soot. 'Oiieofthe chief causes of thisf positedon'sparking p'o 1 r i ts 35 deposit-ion of'soo't is the sudden chilling of ftepit 'and "Wear 'awaythe hot-explosion flame -carryingjincandesfingconsta'nt adjustme centcarbon particles as 'it impinges on the placement of the electrode relatively cool-metal around the plug,"the In the resent inyen explosion cylinder bein usually watercap but in ieu of leaving'f 349 Lacketed. In the case' o mixtures rich in, thereby formin'f a'dead'g droca'rbons, as for exam le the gasolene- `the insulation, provide 'air mixture commonly emp oyed in 'automoof substantially unifor biles, this effect' is es ecially pronounced'. orifices, each too small "The soot produced in t e cylinder is oily in of; ia'ine therethrough. "45 its nature and tends to cling strongly toporcap l chamber forming a ea;

celailnf Another 'important cause of a carsmall perorations'- operatet 'bonffilm formation'is the crackin and 'c'arsures Within. and withoii' boni'zation' of the heavier oilimected into Vat each ohangein pressu the cylinder for pur oses of lubrication. into and out of t e chain 'Eby the repeated comtions: The perforatio nsA pressions and explosions to every part of Arelatively small li'oweu lesa" the 'cylinder chamber as a clin g film ora-Davy 'lampi-n thatth amegjinyl je-* layer, andby'exposure'to the ii'xect exploplosion chamber canno sf e r ion' flame f itf becomes cracked, lbaked and l'positisoot Withinthe caprqip 1er;

Vmetal thimble or cap, forming one pole piecel and inclosin another and-'rodlike pole piece: which at its ase is passed through the usual insulating layer. Approximatel in the center of the cap face 1s=a relative y large orlice registering. with the end of the"y pole piece, and distributed over 'the remaining surface of the 'cap are a number` of 4consider-- ablysm'aller'distributed orices of such diameter. that they will not permit thefpassage of llame. The thicker the metal of the cap the larger, within bounds, may be these perforations. The cap may be chrome steel. Thejother coperating polefpiece is bestI mounted s ulistantiall in the axis of the plug and is insulate from its walls in' the usual .way as by a orcelain sleeve. ItS. sparkinge-terminal is st eaked or coneshaped to t tightly in the arge orifice and 1s so,

l positioned in use withrespect tol this large central orifice of the cap1 thatl the distance` between 'the edgesfof Vt e orifice and' the adjacent conical' pole Vpoint is substantially unlform at all points and the width of the annular clearance is approximately equal screw-thread' tothe diameter of the smaller oricesin n theI face of the thimble, thereby preventing the passage of-ame in either d irection.` By this ole piece' it may made adjustab e in is respect- By this' arrangement' the Ainlting'spark is produced' vat 'the-surface 'of eprotecting cap between -the'ed ofthe oriceaud the omt o'f' the electro" e and 4in contact with v'e' explosive miirturefinfthe cylinder. In mounting the 'p'lng' position, the adjustable threaded conespoint'ed Vp'ole' Apiece' is screwed into `posi-- tonuntil'it engageswith -theorfice and is then givena backyard 'turn Auntil the desired narrow annularfclea'rance is .produced-beiA ofthe -ma-ixr ameinto t e ca chamber; o ,the .cap chamber; positively sweep outthe twee'n the orificeedges and the lcone point.

- type of -foraminous cap, 'thegcapfchamber-g .65 -w 'smallslib-'bbdy of mixture is also-and-Sixnultaneou'slyj ignited.' This by its .equilibrating pressure .tends further :to rev'ent' .elfitran'ce l also contain explosive mixtureand thisV 'andonfthe' release of pressure t e gases my' cham'ber and. clear the ame extinguishing orices 3 of any accumulated soot.

lices being eyenly .distrblllda Ys wee mg action jclears the whole cap chamber," eav-l ingof a sha` e an size adapting it -larged beynd the shoulder-'5 'as shown. The

jcelalnfsleeve is p `ripper portion witha protecting-sleeve 13 v.the cap face and adapt ing no corners or pockets fonaccnmulaticn of-soot. The explosion flame in the engine cylinder cannot stri-ke back into the electrode or cap chamber since with this arrangement all the orifices in the thim ble are too small for the passage of flame. The foraminous protective cap also operates to keep the surace of. theI insulation relatively' cool since A-it prevents .the main flame coming into di rect contact therewith and gases such as may. pass inward through the orifices are cooled somewhat bythe Ime tal,' so that oil coming into' contact with; the 'insulation does 'not' cracker char readily. The usual'insulation .'89

in spark plugs is .porcelain and hotf'p'oree lain surfaces have'acataly'tic-action on vhot `oil favoring the deposition of carbon.`

11n the accompanying illustration I have shown somewhat'dia ammaticall an em- 7 bodiment of the described invention.

` In this showing, Figure l is an elevationl of the spark plu as a Whole; Figi 2 is a 'vertical section o 'tile same; and Fig, 3- is a plan View of the perforated protective cap.. Inthis showing, the threaded pole l carries the lock nuts 3*?) and' asses throu li` the openin -4 which exten s through t e insulating s eeve 2 of procelai'n or vother like material. The opening' 4 is somewhat encollar threaded to .engage the pole-1,' and with the' locknuts 3-3 serves to: adjust .the position of the-pole terminal which has'a coneshaped oint 7.1 The pole pieceLma-y be of any esired diameter provided''the' coned-end be. reduced suiiiciently to :permit en agement with the orifice. Theanipple 8 is rovined withthre'ads 9 and 10 andc'arvries insetjat its lower end the'y foraxninous 105 cap 1 1 of 'relatively vheavg metal vin good thermai' Contact therewit A` threaded@A o'uplin '12 engages thread 9 oi the' -Inipp'levland a so' abuts vagainst the shoulder l-.f 'the porcelain Vsleeve Q ,thus serving 'tofhold "theparts 2 and 8'frmly'. together. "Ehe-pers4 referably provided at its ffices as before noted-fare ofisuch diameter that av i'ame cannot .pass throughthem.4

Terminal 7' may or 'may/ not project Somewhat beyondthecap.

The ,operation'of hsstructureis obvious from 'the foregoing.A In 11Se,..pointed'end -of the'inner electrode may be adj-usted the mannerstatedto Aand from '.thei orifice'in the ,fora'minous cap, with. which it regista-fs;

' until the desired amount of clearance 'obtained. On sparkrng the explesive mixturein the engine cylinder and inflamirig it, there is no possibility of the main flame of A mixture being propagated backward through the relatively small holes of the cap with attendant deposition of soot within the cap While with proper adjustment of the point,

' the .fiame cannot pass backward throughthe large orifice. And with the alternatinging registering orifices in thenforaminous cap may of course beemploye'd though for '/"the sake of simplicity I have shown but a single axial pole piece.

The foraminous protective cap may be employed with any uof the ordinary types of spark plug. i

lVhatI claim is l. A spark plug provided with a protruding electrode or pole piece, a foraminous metal cap inclosingisaid pole piece and having one orifice registering with the end thereof and forming theQopposing electrode, the size of said polepiebe being so proportioned'to that of said orifice, that when the electrodes are operativel positioned the passage therebetween is of ess than flame-passing magnitude, and'all the other orificesof flame-passing magnitude. c

2. A spark plug provided at one ed with a foraminous ca or thimble, all 'butone of the orifices in said foraminous ca-p orthimble being too small to permit flame passage closed by and insulated fromsaid terminal and havingl one end in spark-forming relationship to the edges of a relatively large orifice 1n said foraniinous thimble, the gap therebetween being of' less than flame-'passing width, and the other orifices in said thimble also being so small as to prevent the Ipassage of flame therethrough.

4. In a sparking plug, an electrode chamber comprising a foraminous metal cap 4or sald foramlnous cap being also of less than .40

to the relatively large ing terminal, and, a. second electrode? in'- thimble andconstituting: one electrode,lthe

majority `ofthe Ori'fees in the cap being lso small as to prevent passage of flame therethrough, and a second adjustable electrode l adapted to close the remainderof the orifices to an extent sufficient to prevent flame Apassage therethrough.

5. Asparkplug provided atone end with.

a foraminous cap or thimble all but one' of the orifices in said .foraminous cap or thimble -beingtoo small to permit flame passage l and the remaining orifice being relatively large and an insulated rod-like electrode supported in -theaxis of the plug with one end positioned .in spark-forming relation to said foraminous thimble, ,and closing said relatively large orifice to an extent suiiicient I 'to' prevent flame passage therethrough.

.6. A -spark plug comprisin an electrode surrounded by a projecting s eeve of insu- I lating material, -a fibrous sleeve covering a vpart gf said insulated electrode, a metallic sleeveinclosing the remainder of said insulated electrode and forming a second elec trode, and a foraminous cap carrie-d by sai.

second electrode having a'relatively large central orifice registerin with the terminal ofthe first electrode an forming therewith a spark gap too small to permit flame passage,and also having a plurality of other orifices Vtoo small to permit flame passage therethrough.

7 In ai parking device having ametal bod-yyapdl rovided with electrodes spaced AAinsulation, a foraminous cap lof by poi-:cela

relativelylhealvy metal forming one electrodev terminal'and inclosing said porcelain and in heat-conducting relationship tov the'\ lmetal" body of 4said sparking device, all bu`t`oneof the orificesin said cap being relatively minute and v,adapted to extinguish flamepass'- ing therethroughand the remaining-,orifice bemg of' greater magnitude, andan adjustable electrde' Within said cap and having an end adapted to register with the larger orifice and' form an annular spark gap therewithA of less thanfflame-transmitting'magnitude.

8. A sparking device comprising an-elec- I trode provided with a foraminous' metal cap or thimble formin -an electrode chamber lated'from and supported Within said elecand a vertically-a justable electrode insutijodeA chamber, said electrode chamber beprovided with a relatively large orifice i'iegister with the end of said adjustable electrode and of size` and form adapting it\` to form` with said end an annular spark gap of less than flame-transmitting magnitude and said chamber being also provided with' a plurality `of other orifices, all of which are of less than flame-transmitting magnitude.

9. A sparking device comprising an electrode provided with a foraminous metal cap or thimble forming an electrode chamberand a Nertic-ally adjustable electrode havingv a coned -end and insulated from and supported Within said electrode chamber, said electrode chamber being provided with an. orifice registering With the coned end of said adjustable' electrode and of somewhat I smaller/diameter than the body' of said ad- 1 justable electrode,l said orice being adapted to form with said coned end an annular 1o- Aspark gap of less than flame-passing magnil tude, and said chamber being 'also prlJvided with a. plurality of other orices, all of Which are of less than ,flame-transmitting magnitude.l

In testimony whereof, I alx m5; signa- Y15 ture in the vpresence of Witnesses. v VILLIAM H. MCNUTT. .Wtnessesz LOUIS LEAVITT,

JN0. MORGAN.' 

